21 Cypress Ave
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95659, -122.53871
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,318,000 ($2,040,000–$2,596,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 6,795 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$80,381 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Nov 26, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Kentfield
104 substantial renovation & housing permits over 24 months (41.3 per 1,000 parcels vs. 16.4 citywide baseline) (#7 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Kentfield)
Watchouts & Due Diligence
- ! Mapped flood awareness zone (Zone X: 0.2% annual chance flood hazard (shaded X))
all of the lot of the parcel intersects Zone X: 0.2% annual chance flood hazard (shaded X). Outside mandatory federal SFHA insurance rules, but check local drainage and finished-floor requirements.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! Delayed or open permit activity on this parcel
Plumbing / water heater / sewer (166637): Issued after 2 mo — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 4 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 34 Wolfe Grade (0.19 mi SE, applied). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
- ! Year 1 Prop 13 tax reset (~$27,107/yr at $2,318,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,259/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Parcel & Assessor
- Lot size:
- 6,795 sq ft (0.16 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 21 CYPRESS AVE
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 6,795 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone X: 0.2% annual chance flood hazard (shaded X) (all of the lot) · FIRM panel 06041C0458F, effective March 16, 2016
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $2,040,000 – $2,596,000 · Status: Off market
HUD Small Area FMR (ZIP 94904) · FY 2026
Studio $2,260 · 1BR $2,710 · 2BR $3,280 · 3BR $4,190 · 4BR $4,340
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 34 Wolfe Grade (Applied)0.19 mi SE
In "Applied" for 2.8 yr (since Jan 17, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
- Plumbing / water heater / sewer (166637) (Issued)On this parcel
Issued after 2 mo — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
- Plumbing / water heater / sewer (86042) (Applied)On this parcel
Pending in review for 6.3 yr — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
- New home at 49 Laurel Grove Ave (Issued)0.16 mi W
Active in "Issued" for 9.3 yr (first record Jul 18, 2017) with no new permit activity recorded in 9.1 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Salinas General Contractor (2 on parcel, 2 in ½ mi · Remodel / interior alteration); Royal Pools Of Santa Clara (1 on parcel, 1 in ½ mi · Pool / spa); Gutierrez Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Lightning Services (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Peter Levi Plumbing (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 180595 | Pool / spa | Issued | Iss. Nov 26, 2025 | $116,767 | Residential In Ground Pool With Auto Safety Cover - 144 Sq Ft |
| 168041 | Remodel / interior alteration | Issued | Iss. May 6, 2021 | $47,250 | Bedrm & Bath Remodel - Express |
| 166637 | Plumbing / water heater / sewer | Issued | Iss. Dec 21, 2020 | $15,000 | Generator |
| 86042 | Plumbing / water heater / sewer | Applied | App. Jul 17, 2020 | — | Generator |
| 158000 | Remodel / interior alteration | Issued | Iss. Mar 22, 2018 | $43,825 |